Imitation assessment and its utility to the diagnosis of autism: evidence from consecutive clinical preschool referrals for suspected autism.

The present study sought to examine imitation difficulties as a risk factor for autism. Imitation aptitude was examined in 86 preschoolers suspected of autism (1.9-4.5 years) using the Preschool Imitation and Praxis Scale (PIPS). Differences between imitation, language, motor age-equivalents and nonverbal mental age were used to predict the diagnosis of autism. Multidisciplinary team diagnoses and ADOS-G classifications were used to differentiate children with autism spectrum disorders and non-spectrum developmental disorders. Two factors were found to be significantly associated with autism using simple logistic regression analyses: procedural imitation delay and receptive language delay. In a multivariable setting, only procedural imitation delay remained a significant predictor of autism. Results are new to the literature and require replications.